Recent studies have suggested that trans fatty acids in food products and food intermediates can be detrimental to the general health and well being of consumers in that it contributes to obesity and other health related issues.
Trans fatty acids are unsaturated fatty acids in which the hydrogens of a double bond (or unsaturation) are on opposite sides of the molecule. The trans isomer of the fatty acid causes the carbon chain to assume a straight-chain configuration similar to that of a saturated fat. Trans fatty acids are primarily formed through the metal-catalyzed process of hydrogenation, however they have also been found to form naturally at low levels in cow's milk. By hydrogenating oils through industrial processing, hydrogen atoms are added to unsaturated sites on fatty acids, creating a larger population of saturated fats in the oil. In a partially-hydrogenated oil, some of the unsaturated fatty acids remain. However, the processing causes some of the double-bonds of the unsaturated fatty acids to undergo isomerization to the trans configuration.
Partial hydrogenation of fats was introduced into the U.S. food supply beginning in 1910. The practice was put into widespread use in the 1940's in order to make semisolid fat products. The process of hydrogenation raises the melting point of a fat and increases the solid fat content. The stability of the fat is greatly enhanced through hydrogenation by reducing susceptibility to oxidation and subsequent rancidity. Therefore, positive contributions to shelf-life, texture and taste of food products are imparted by hydrogenated and partially hydrogenated fats.
Some scientific evidence shows that the trans fat that results from partial hydrogenation of oils raises the total cholesterol in humans to a greater extent than saturated fats. Trans fat is known to increase blood levels of low density lipoprotein (LDL), so-called “bad” cholesterol, while lowering levels of high density lipoprotein (HDL), known as “good” cholesterol.
Cyclodextrins have been used principally for the encapsulation of insoluble compounds on a molecular basis in order to enhance stability, reduce volatility and alter solubility as well as to increase shelf life of certain products. Such prior uses of cyclodextrins have been limited to flavor carriers and protection of sensitive substances against thermal decomposition, oxidation and degradation. In addition, more recently, cyclodextrins have also been used to remove fatty acids and cholesterol from animal fats and to remove cholesterol and cholesterol esters from egg yolks.
One potential solution to the high cholesterol problem teaches the treatment of the foodstuffs themselves with cyclodextrins rather than treatment of the consumer. U.S. Pat. Nos. 5,498,437; 5,342,633 and 5,063,077 discuss various processes for the removal of cholesterol and cholesterol esters from egg yolks, meat, animal fats, etc. It is thought that by reducing the level of cholesterol in such foodstuffs that overall levels of cholesterol can be reduced in consumers. However, processing steps to such foodstuffs increases the cost of delivering such products to market.
In some instances, a thickened fat is desired to provide dimensional stability (e.g., to minimize fluid flow or keep a fat ingredient in a particular location in a food article). At present, only three techniques for providing a thickened fat such as for use in a food product are practical. The first, hydrogenation, as described above, while useful and widely practiced undesirably results in the generation of trans fatty acids. The second technique involves addition of silicon dioxide to an oil. For example, U.S. Pat. No. 3,669,681 describes preparing a shortening for products which are heated prior to consumption, wherein edible oils are mixed with silicon dioxide and a bridging compound with the result being a shortening that is asserted to not weep or run at elevated temperatures while retaining desirable mouth feel characteristics of the untreated oil.
While useful, current food regulatory restrictions restrict employment of this technique. The third technique involves addition of sufficient amounts of hardstock, whether naturally occurring (such as palm oil hardstock) or synthetic (such as produced by hydrogenation), to an oil to provide desired amounts of thickening or hardening. Again, while useful, current consumer heath sensitivities favor minimization of consumption of such hardstock ingredients.
Fat compositions have been thickened by binding the fat with cyclodextrin by mixing the fat with a cyclodextrin that has been solubilized by a solvent, preferably water, in a batch process. This batch process is described in U.S. patent application Ser. No. 11/158,747; Titled: VISCOUS FAT COMPOSITIONS HAVING LOW AMOUNTS OF TRANS-FAT, METHODS AND PRODUCTS, filed Jun. 22, 2005.